All the harnesses has this problem, other tabs in the harness rule form are fine except Design tab.

I have verified the pzHarnessRuleFormUtils.js and its present.

Getting the below error in the console of Chrome Dev tools :

Uncaught TypeError: Cannot read property 'selectSingleNode' of null
at pega.ud.Section.buildSection (VM13776 pzformframe_1846726241!pzformframeui_1357328730!!.js:3170)
at pega.ud.Section.buildInclude (VM13776 pzformframe_1846726241!pzformframeui_1357328730!!.js:3073)
at pega.ud.Section.buildContainer (VM13776 pzformframe_1846726241!pzformframeui_1357328730!!.js:2971)
at pega.ud.DVManager.buildContainer (VM13776 pzformframe_1846726241!pzformframeui_1357328730!!.js:8542)
at pega.ud.DVManager.buildHarness (VM13776 pzformframe_1846726241!pzformframeui_1357328730!!.js:8542)
at pega.ud.DVManager.getHarnessHtml (VM13776 pzformframe_1846726241!pzformframeui_1357328730!!.js:8542)
at pega.ud.DVManager.buildForm (VM13776 pzformframe_1846726241!pzformframeui_1357328730!!.js:8542)
at pega.ud.DVManager.xmlLoaded (VM13776 pzformframe_1846726241!pzformframeui_1357328730!!.js:8542)
at pega.ud.DVManager.loadAndRegister (VM13776 pzformframe_1846726241!pzformframeui_1357328730!!.js:8542)
at doOnLoadPRXML (VM13901 dvscript_1220012183!!.js:2)